1. Field of the Invention
This invention relates to a new dental impression tray, used in combination with moldable material, for obtaining an accurate impression of the jaw and gingiva areas of the mouth of an edentulous patient.
2. Prior Art
In dentistry, an impression is often used to create an imprint likeness of an edentulous patient's jaw and gingiva areas in preparation for restoration of dental structures such as complete or partial dentures. The ability of the dental technician or dentist, hereinafter referred to as “operator”, to obtain a satisfactory impression is influenced by the dental impression tray, hereinafter referred to as either “dental impression tray” or “dental tray”, used in combination with moldable material, hereinafter referred to as “impression material”, to obtain the impression.
The accuracy of the impression, to a large extent, will depend upon how well the dental tray is received in the patient's mouth. In order to gain a more accurate impression, numerous types of dental trays have been developed. Some dental trays are designed for numerous applications and are called standard dental trays. Some dental trays are specifically designed for a single purpose such as a dental tray designed for only one side of a patient's mouth. Some dental trays are designed for use with a patient that still has at least some of their teeth as disclosed in U.S. Pat. No. 6,457,973 B1, issued on Oct. 1, 2002 to Fetz et al. Some dental trays are adjustable to allow one dental tray to fit a large number of patients as disclosed in U.S. Pat. No. 6,428,315 B1, issued on Aug. 6, 2002 to Prestipino et al. Some dental trays are designed to allow impression material to be placed in the patient's mouth through the dental tray after inserting the tray in the patient's mouth as disclosed in U.S. Pat. No. 6,641,393 B2, issued on Nov. 4, 2003 to Trichas. Some dental trays, called enhanced trays, are larger devices that that help lift the patient's tongue up and away from the jaw and gingiva areas to assist with obtaining an impression. It is also very common for the dental trays in the prior art to require the use of adhesive to help retain the impression material onto the dental tray during the impression procedure. The adhesive is odorous and distasteful, making the use of adhesives unpleasant for the patient.
While each of the different trays in the prior art do address certain problems with obtaining an accurate impression, they also create new problems or do not work well with today's wide range of impression materials. One problem is that prior art causes excessive impression material to be expelled backward into the throat of the patient causing discomfort and sometimes gagging. Another problem is that the prior art are not built to match the anatomy of an edentulous patient's jaw and gingiva areas. This can lead to the dental tray deforming the patient's jaw and gingiva areas, thus preventing an accurate impression. This also leads to having to use excessive impression material to obtain a reasonable impression, which contributes to a patient's discomfort and gagging. Yet another problem is that the prior art does not work well with the entire range of impression materials that are now available from extralight to very heavy in density due to openings in the dental trays having either too small of openings or too large of openings. Where the dental tray has small openings, the dental tray does not distribute the medium to very heavy density impression materials well. Where the dental tray has large openings, the dental tray does not retain the extralight to medium density impression materials well. This causes the operator to use impression materials that work with the dental tray when other types of impression materials or a combination of different types of impression materials would provide better results. Yet another problem is that the prior art does not provide a means for uniformly distributing pressure to the dental tray to seat the dental tray and impression material in the patent's mouth. When inserting the dental tray and impression material in the patient's mouth, the operator must push on the tray to seat it around the jaw and gingiva areas. Since the prior art does not provide a way to distribute this pressure uniformly to the dental tray, often the dental tray will improperly seat deeper at the point where the pressure is applied and create an inaccurate impression. Yet another problem is that the prior art does not provide a way to allow the operator to keep their hand, wrist and arm in an ergonomically correct position while placing the dental tray and impression material in the patient's mouth and while placing pressure on the dental tray to seat the dental tray and impression material. At best, this can lead to the operator's fatigue, discomfort and loss of productivity; and, at worse, can lead to the operator becoming injured by having to repetitively place their hand, wrist and arm in awkward positions.
Therefore, there is a need in the art for a new and improved dental tray that provides an accurate impression of an edentulous patient's jaw and gingiva areas by more closely matching the anatomy of the edentulous patient's mouth so that the patient's jaw and gingiva areas are not deformed or influenced by the dental tray and the impression material is retained by the dental tray during the impression procedure without the use of adhesives; by accommodating the use of the entire range of impression materials that are now available so that the best impression material or the best combination of impression materials can be used to obtain the impression; by providing a means to uniformly transfer pressure to the dental tray so that the impression material is correctly seated in the patient's mouth to obtain an accurate impression with less discomfort to the patient; and by providing a dental tray that allows the operator to maintain their hand, wrist and arm in an ergonomically correct and comfortable position while placing the dental tray and impression material into the patient's mouth and while seating the dental tray and impression material in the patient's mouth during the process of obtaining the dental impression of the edentulous patient.